Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

it doesn't work because ASP .NET id is mainly different from HTML id. simply because when ASP .NET is executed, it would be replacing its id to name (in my experience). also, getElementById is pratically exclusive only for div and span tags.
try this if it works:

<div id="someText" style="display:none;">This is a text! You saw me when you clicked the button.</div>
<input type="button" value="Click to show text" onClick="document.getElementById("someText").style.display='block';" />

<div id="someText" style="display:none;">This is a text! You saw me when you clicked the button.</div>
<input type="button" value="Click to show text" onClick="document.getElementById('someText').style.display='block';" />

This article shows how to create and access 2-dimensional arrays in JavaScript. It includes a tutorial in case you are just trying to "get your head wrapped around" the concept and we'll also look at some useful tips for more advanced programmers.
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JavaScript can be used in a browser to change parts of a webpage dynamically. It begins with the following pattern: If condition W is true, do thing X to target Y after event Z. Below are some tips and tricks to help you get started with JavaScript …

The viewer will learn the basics of jQuery, including how to invoke it on a web page.
Reference your jQuery libraries: (CODE)
Include your new external js/jQuery file: (CODE)
Write your first lines of code to setup your site for jQuery.: (CODE)

The viewer will learn the basics of jQuery including how to code hide show and toggles.
Reference your jQuery libraries:
(CODE)
Include your new external js/jQuery file:
(CODE)
Write your first lines of code to setup your site for jQuery…